Granular product, such as grain or corn may be stored and shipped in bulk containers such as railroad tank cars, tank trailers, and pipelines for transportation from one site to be delivered to another site. The delivered product exits from the storage compartment of the transport carrier, such as its tank trailer, and then flows through piping upon the trailer for delivery by hose or further piping to a storage facility or location of usage. In dry bulk hauling, such as of pellets, powders, and grains, the seal integrity at the pipe connection is essential to prevent contamination of the material. It is desirable to provide not only cleansed air that is used in the unloading process, but also to reduce the volume of noise involved in the discharge. The pellets or powders unloaded from gravity gate valves or hoppers located on the bottom of the tank car, exit through tee's that are attached to the bottom of a hopper which normally connect with a collection of pipes, that convey air under pressure to assist in the unloading process. A vacuum or air stream from a pneumatic conveyor system created in the piping system accelerates the unloading of dry bulk products from the hopper.
During the unloading process, the hopper of the tank trailer must be completely emptied of all of the dry bulk product to prevent contamination of any later loads. In addition, not only must the unloading air pressure system be 100% effective in removing the transported cargo, but it is highly necessary that the air itself be reasonably purified, so as not to add any contamination to the discharging bulk granular material, during unloading. Any residue that remains may contaminate subsequent loads or may generate mold or other deleterious substance, which can contaminate subsequent loads.
Presently, the bulk transporting industry favors downloading dry product from tank trailers by pneumatic systems. A pneumatic system begins with a blower mounted to a tractor, such as a truck. When turning at high revolutions per minute, the blower forces air into a discharge pipe that pressurizes the collection pipes below a trailer. The pressurized air then attracts by venturi flow the granular material, by gravity out of the tank trailer, and it is conveyed within the stream of the pressurized flowing air, to the site of storage. The pressurized air then delivers the dry bulk product from the collection pipes to the delivery point, commonly by way of a hose. As known, a typical blower generates much noise, and permits traces of oil, grease, and dirt to enter the discharge pipe. All of these are detrimental. As mentioned above, contamination remains of high concern to dry bulk haulers, particularly where the cargo may be subsequently used in food stuffs or as ingredients to food products. During downloading of dry bulk products, contamination must be lowered, if not eliminated, in ordered to meet food safety standards. In addition, any noise levels generated during unloading must be lowered generally to conform to local noise ordinances.
In order to reduce or eliminate contamination and noise, it is known to use an inline air filter for dry bulk tank trailers. Typically such filter devices have a housing having an inlet, a filter element, a filter guide, and an outlet. The filter guide is used to align the filter element near the outlet to ensure that a proper seal exists between the filter element and the outlet. The filter guide consists of guide wires that are welded in an outlet pipe of the housing in the path of air flow. Over time the guide wires are subject to failure and breakage. Once the guide wires fail and due to the guide wires being in the air path, the wires are sucked into the bulk material being delivered. As can be appreciated, if the bulk material is an ingredient for food, the food becomes contaminated with the guide wires and dangerous if the guide wires are consumed by individuals. Another problem associated with the guide wires is that the wires create an obstruction in the air flow path through the filter element. This may lead to a decrease in the efficiency of the pneumatic system.
The present disclosure is designed to obviate and overcome many of the disadvantages and shortcomings experienced with prior filter guides. Moreover, the present disclosure is related to a filter guide ring that eliminates the possibility of the filter guide contaminating product or having any guide wires in the air flow path.